1. Field of the Invention
This invention relates to a hybrid circuit device wherein a base plate having any desired form of circuit provided thereon is externally connected to an integrated circuit, and more particularly it pertains to construction adapted to reduce the thickness of such device.
2. Description of the Prior Art
Presently, most electronic circuits have been provided in the form of an integrated circuit. However, difficulties have been experienced in fabricating, in the form of an integrated circuit, an inductance containing circuit such as a delay line circuit which consists of a combination of coils and capacitors, for example. Thus, in the case of a circuit device including a circuit which is difficult to provide in the form of an integrated circuit, it is required that such a circuit be externally connected to the integrated circuit. Such requirement arises when it is attempted to provide a buffered delay line by combining a delay line with a saturation type logical circuit using TTL elements, for example. U.S. Pat. No. 4,506,238, for example, discloses a hybrid circuit device wherein a base plate supporting a delay line circuit comprising coils and capacitors, is superimposed upon flat package of an integrated circuit; the two circuits are connected together through terminals of the flat package; and external terminals are exposed through the dual in-line package (referred to as DIP hereinafter).
In such a conventional hybrid circuit device, however, the coils 1 and capacitors 2 are all mounted on the base plate 3, i.e., on the side opposite to the flat package 4, as shown in FIG. 5. The base plate 3 and flat package 4 are substantially equal in width to each other, and the two circuits are connected together through upwardly-bent terminals 5 of the flat package 4 at side face of the base plate 3. Also at side face of the base plate 3, external terminals 7 are connected to terminals 6 projecting out of side face of the flat package 4. In this way, it is required that all the connections between the external terminals 7 and the terminals 6, between the base plate 3 and the external terminals 7 and between the base plate 3 and the terminals 5 be provided adjacent to side face of the base plate 3, thus, the connecting structure turns out to be complicated so that short-circuiting is liable to occur. Difficulties are encountered in an attempt to mount circuit components at the side of the flat package 4 where the complicated connecting structure is provided, and hence during the assembling procedures, the flat package 4, base plate 3 and circuit components constituting the delay line are superimposed upon each other. Obviously, with such an arrangement, it is difficult to reduce the thickness T of the DIP shown by the alternate long and short dash lines in FIG. 5. In the case where such hybrid circuit device is mounted onto another circuit board, together with other circuit components, the thickness T of the DIP will be greater than the thickness of any of the other circuit components, and this is undesirable from the standpoint of making flat the circuit board as a whole.